#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
int main()
{
 pid_t id = fork();
 if(id < 0)
 {
     //创建失败
     perror("fork");
     return 1;
 }
 else if(id == 0)
 {
     //child process(task)
     while(1)
     {
         printf("I am child, pid: %d, ppid: %d\n", getpid(), getppid());
         sleep(3);
         break;
     }
     exit(0);
 }
 else 
 {
     //parent process
     while(1)
     {
         printf("I am father, pid: %d, ppid: %d\n", getpid(), getppid());
         sleep(1);
     }
 }

 printf("you can see me!\n");

 sleep(1);
 return 0;
}

